Netflix slow on Verizon or Comcast? A VPN might speed up that video

ISPs could throttle traffic if they want—but Netflix can play dirty tricks too.

Since reporting on Netflix data that shows months-long declines in streaming performance on Verizon and Comcast, we've heard from several readers who say they've eliminated video problems by using VPN services.

"Netflix on Comcast tanked for us in the past month or two," one commenter wrote. "We would spend more time buffering than actually watching video. Once we set up a VPN with UnblockUs it magically went away."

Further Reading

Another reader sent us bandwidth statistics from his home that compared traffic on Comcast to traffic over a VPN, saying the poor Comcast performance proves that "they throttle Netflix heavily." Similar accusations have been leveled against Verizon.

No one has actually shown beyond a shadow of a doubt that ISPs directly throttle Netflix traffic. Throttling may be legal in the US now that Verizon has convinced a court to strike down net neutrality rules, and Netflix has criticized ISPs, but it hasn't gone so far as to allege throttling. Netflix performance does vary by ISP, but we can't rule out the possibility that Netflix's own practices are causing bad outcomes for consumers. It's also possible that no one is doing anything particularly nefarious.

What's clear is that somewhere in the path from Netflix servers to consumers' homes, there is congestion. It's also clear that some people have improved their own streaming video by using VPNs (virtual private networks) or third-party DNS (Domain Name System) services. (UnblockUs, mentioned above, is not technically a VPN service but it achieves a similar effect by changing your DNS settings.)

There's no guarantee that using a VPN will improve things—it could even make them worse. But if you're desperate, it may be worth a try.

Routing around congestion

Sandvine cofounder and CTO Don Bowman talked to Ars this week about why VPN and DNS services can help relieve congestion for certain users. He also talked about the types of shady tactics both video streaming providers and ISPs could employ in their ongoing battles and how that could harm home Internet users.

VPN services route an Internet user's traffic through data centers in different locations and are usually sold to people who seek anonymity or to evade country-specific blocks (such as video content blocked in certain countries).

As a side effect, a VPN may route your traffic away from congested servers and links that would normally serve up video to your home. Netflix and YouTube store video caches in many locations, and data can take multiple paths to its final destination.

"Imagine you're in the US and that you are on a carrier that existed in multiple states and time zones, you can VPN to the West Coast from the East Coast and end up getting the idle servers that are there, just sitting and waiting for people to get out of school and off work and so on," Bowman said.

BTGuard and Private Tunnel are examples of VPN services. If you consistently get better performance with a VPN than without, it could be a sign of a "systematic dispute between vendors upstream." In the past, Verizon and Comcast have each had disputes with bandwidth providers over whether the ISPs should be paid to carry Netflix traffic.

These disputes can lead to the links between networks not being upgraded quickly enough. This affects all traffic, but is more noticeable for bandwidth-hungry streaming video.

"If a VPN consistently behaves better, it's proof that there is something along the path that doesn't have enough capacity," Bowman said. "It might be a link [between providers] or it might be a server. There may not be enough servers in the server farm, there may not be enough capacity between the two carriers."

This would not be proof that Verizon or Comcast is throttling Netflix or any specific application.

"The only way you could draw that conclusion is if you guaranteed [traffic] came from the same path and server but that somehow the VPN made it look different," Bowman said. "If you could VPN to the same server you were getting the streaming from, using exactly the same path and then it behaves better, that would be pretty conclusive proof."

It's important to know that Netflix and your ISP aren't the only two companies responsible for carrying traffic. Bits have to travel across numerous networks, and problems could crop up in any of them.

"Streaming content exists on a set of CDN (content delivery network) providers from more than one company, and they in turn have many servers in each location, and they have multiple locations, and each of those locations has a set of intermediate ISPs which connect to a set of intermediate ISPs which connect to the eyeball ISP you're on," Bowman said. "It's very difficult for even networking professionals who are in those locations to know how a packet will flow."

CDNs can take multiple paths to a consumer ISP and will hit transit networks on the way there. The receiver of content is responsible for showing how it can be reached, while the sender is responsible for how it reaches the endpoint when there are multiple choices, Bowman explained. Using a VPN can force the sender to make different choices than it otherwise would. Sandvine research suggests that there are generally no systemic problems within consumer ISP networks—it's the interconnects between networks where trouble arises.

Using a VPN takes your traffic away from the shortest path by distance, but may be faster in cases when the path would otherwise be congested. Networks generally aren't intelligent enough to automatically route around congestion.

"A network is based around packet switching, and every packet is treated independently," Bowman said. "At each location it's got a set of ways to get to its next location. It doesn't know that two hops down it gets busy."

In the future, it may be easier to pinpoint the source of problems. Speed test tools from Netflix and Google today show averages across wide swaths of users. Bowman said he'd like to see more advanced tools that benchmark the interconnections between specific network providers.

You're rolling the dice by using a VPN, betting that you might get a faster path. That bet may backfire. "In general it makes things worse for the user," he said. "There's a reason they're trying to do this optimization, to give you the best experience, and you're breaking it."

130 Reader Comments

Solution to this is simple. Pick if you want to be ISP (dumb pipe) or you want to deliver content. No connection what so ever between the two allowed.

Would solve all problems in a jiffy. Same with mobile. You can either provide towers or actual communication (if you don't like the state taking care of the strategic infrastructure and content and service providers buying access).

Solution to this is simple. Pick if you want to be ISP (dumb pipe) or you want to deliver content. No connection what so ever between the two allowed.

Would solve all problems in a jiffy. Same with mobile. You can either provide towers or actual communication (if you don't like the state taking care of the strategic infrastructure and content and service providers buying access).

This problem would persist even if they were only an ISP. They have an obligation to raise profits, and holding Netflix hostage until Netflix pays more is one way to do that.

Netflix wants to peer directly with ISPs and put its video caches inside the ISP data centers. The offer is "free," but ISPs would have to host equipment dedicated to Netflix, letting Netflix save money on transit fees.

Isn't this itself Anti-Net-Neutrality? Netflix is asking for a privileged position above other content providers, and they're "paying" the ISP by reducing the expensive inbound transit that ordinarily occurs with Netflix. If the ISPs were to charge Netflix, this would only become explicit.

When you look at it this way, it even makes sense that Netflix "does not seem overly concerned about Net Neutrality".

"If someone comes to you and says, 'hey I'm big, I want differentiated service, I'd like to move close to your consumers, so can you please make 40 inches of space and 5,000 watts of power available at 100 sites, thanks very much,' you would normally say, 'I'm in the business of selling that—here's my price list."

Well, it does seem like he has a point here. ISPs should be a dumb pipe, but that doesn't mean they should also pay for the originating server - that cost clearly belongs to Netflix. Of course the question then becomes who decides how much this server costs. It's easy to see how the quest for profit can screw with the idea of co-operating to provide a service.

If I am following all this correctly, it gets into something called 'hot potato / cold potato' routing. IOW, does Netflix dump the traffic at the first available point, or does Netflix have private fiber to get it as close as possible to the end user. If the former, then they are at the mercy of the backbone carriers. If the latter, they are probably paying a pretty penny for all that fiber/bandwidth.

It isn't only Netflix that this is a problem with. While using my Apple TV I noticed that content from Apple is slow compared to traffic from non-Apple sources. This is no coincidence and Verizon and Comcast isn't the only one throttling.

Until people like Apple and Netflix start lobbying Congress to do something about the consumer abuse, it will not change a thing. And having people say 'put your money where your mouth is' isn't a solution when you have no competition in the first place, or all of the competition is performing the same customer abuse.

Solution to this is simple. Pick if you want to be ISP (dumb pipe) or you want to deliver content. No connection what so ever between the two allowed.

Would solve all problems in a jiffy. Same with mobile. You can either provide towers or actual communication (if you don't like the state taking care of the strategic infrastructure and content and service providers buying access).

This problem would persist even if they were only an ISP. They have an obligation to raise profits, and holding Netflix hostage until Netflix pays more is one way to do that.

In that case they would not have competing offerings that they themselves provide and thus the value of their offering would go down if the users can't use it for anything useful. Try selling internet access but with all google services blocked and see if anyone buys it.

Streaming large files is a poor way of using network resources. Downloading via a peer to peer protocol for offline viewing is a much more clever and efficient way of using these resources. Unfortunately, the latter doesn't suit the powers that be.

Why don't more streaming providers allow direct download and offline viewing? Why couldn't I just have downloaded all of the second season of House Of Cards last night?

I'm sure you probably can find all the shows available for download somewhere. But Netflix doesn't make money off those.

How do you stop pirating under your plan?

Same like pirating is stopped for music. By offering a service that is actually better than pirating. People are by default lazy and if they have a choice they will rather pay a bit than bother with pirating (this of course is not valid for people who can barely buy food as they have somewhat more important things to spend their money on and most likely have us to thank for that condition).

Streaming large files is a poor way of using network resources. Downloading via a peer to peer protocol for offline viewing is a much more clever and efficient way of using these resources. Unfortunately, the latter doesn't suit the powers that be.

P2P is the modern day silver bullet. Clogged pipes? P2P. Losing hair? P2P. Wife sleeping with the mailman? P2P.

Edi: I could make a better argument that Usenet, Sickbeard, and Couch Potato could be a better combination, especially considering most good Usenet providers have better retention (and selection; what if what I want ISN'T popular) than a lot of "Joe Random", and aren't subject to the up and downs of seeds coming and going.

"Imagine you're in the US and that you are on a carrier that existed in multiple states and time zones, you can VPN to the West Coast from the East Coast and end up getting the idle servers that are there, just sitting and waiting for people to get out of school and off work and so on," Bowman said.

Load Balancers?

Quote:

Using a VPN takes your traffic away from the shortest path by distance, but may be faster in cases when the path would otherwise be congested. Networks generally aren't intelligent enough to automatically route around congestion.

I guess I must be one of the lucky ones. I view (stream) a lot of Netflix and YouTube in HD. (Or what Netflix calls "super HD", though I find YouTube's best HD a bit better quality-wise on much of their content.) I rarely encounter buffering (maybe once every 10 days or so).

Perhaps it helps that I'm an internet-only customer and receive my local stations over-the-air. (No cable channels on the "pipe" to my home to clutter things up.) Perhaps it also helps that I have two high-speed cable/internet companies in my neighborhood--(WOW and Mediacomm). They both are always trying to outdo each other in performance and customer service. Competition is a very good thing!

Same like pirating is stopped for music. By offering a service that is actually better than pirating. People are by default lazy and if they have a choice they will rather pay a bit than bother with pirating (this of course is not valid for people who can barely buy food as they have somewhat more important things to spend their money on and most likely have us to thank for that condition).

Actually, that is less about lazy and more about "Can be secure that the download does not have a virus in it that will mess up your machine!"

That is the main reason why I use Rhapsody Win 8 App for all or almost all my music listening today, I don't have to worry anymore about "Oh poop..... this thing had a virus in it and my anti-virus/anti-malware did not catch it!"

Ah yes. It is well known that viruses spread through video and sound files. While it technically might be possible I haven't heard about anything of the sort in the wild. Was a bug in gif or jpeg interpretation in windows a bunch of years ago that could result in buffer overflow but it was patched and is only case I've heard of.

ISPs especially cable companies have a tendency to oversell their bandwidth and the ISPs may not actually be lying about throttling these services, but may be doing bandwidth prioritization. Meaning business class services or unknown encrypted services would get a higher priority than streaming video. So in the end streaming video services get a lower service level and thus lower bandwidth guarantees.

So they may not have any rules that directly relate to Netflix, but may have rules that would lower the overall available bandwidth for non-priority services...

I am not defending them, but restating the obvious that ISPs should not be overselling their bandwidth - I think if you pay for a 30Mb or 60Mb pipe there should be some guarantee...

I would be interested to see if their business offerings have the same issues. In my experience once I switched to the business class service my bandwidth was always spot on.

Solution to this is simple. Pick if you want to be ISP (dumb pipe) or you want to deliver content. No connection what so ever between the two allowed.

Would solve all problems in a jiffy. Same with mobile. You can either provide towers or actual communication (if you don't like the state taking care of the strategic infrastructure and content and service providers buying access).

This problem would persist even if they were only an ISP. They have an obligation to raise profits, and holding Netflix hostage until Netflix pays more is one way to do that.

In that case they would not have competing offerings that they themselves provide and thus the value of their offering would go down if the users can't use it for anything useful. Try selling internet access but with all google services blocked and see if anyone buys it.

Two things,

1) This assumes that users have an alternative high speed connection to swap to. I live in a suburb of DC and I have no option but Comcast at my residence. If Comcast started degrading my service (maybe they do already?) I have absolutely no choice but to live with it. I'd keep paying for it because I have no other way to keep my job (I work from home usually).

2) This is not always obvious to the end user, and it's in the ISP interest to make it not obvious. Consider the recent Ars articles about how we have no idea if Comcast is throttling connections. I'm sure Comcast is happy to keep it that way too.

So while I agree the ISPs should not have a hand in the media business, something more needs to be done than merely creating that limitation. There needs to be competition, or oversight to force fair play across internet services.

Solution to this is simple. Pick if you want to be ISP (dumb pipe) or you want to deliver content. No connection what so ever between the two allowed.

Would solve all problems in a jiffy. Same with mobile. You can either provide towers or actual communication (if you don't like the state taking care of the strategic infrastructure and content and service providers buying access).

This problem would persist even if they were only an ISP. They have an obligation to raise profits, and holding Netflix hostage until Netflix pays more is one way to do that.

In that case they would not have competing offerings that they themselves provide and thus the value of their offering would go down if the users can't use it for anything useful. Try selling internet access but with all google services blocked and see if anyone buys it.

Two things,

1) This assumes that users have an alternative high speed connection to swap to. I live in a suburb of DC and I have no option but Comcast at my residence. If Comcast started degrading my service (maybe they do already?) I have absolutely no choice but to live with it. I'd keep paying for it because I have no other way to keep my job (I work from home usually).

2) This is not always obvious to the end user, and it's in the ISP interest to make it not obvious. Consider the recent Ars articles about how we have no idea if Comcast is throttling connections. I'm sure Comcast is happy to keep it that way too.

So while I agree the ISPs should not have a hand in the media business, something more needs to be done than merely creating that limitation. There needs to be competition, or oversight to force fair play across internet services.

Well best option is to have state take care of the infrastructure. While companies sell services based on it. Problem here is that you could sell something like that in EU but in US it would be called communism or some other shit.

Other version is having laws that force selling the access to other companies. EU has in general also relatively few owners of the hardware but the competition levels are still orders of magnitude above anything that is available in US/UK/australia.

So yea it's not a full solution by itself but it would be a huge step on the way. Also when you have many smaller companies that have opposing interests their lobbying efforts will work against each other. Instead today we have a vertically integrated corporations that lobby very well for their own profits and ruin for the consumers.

Maybe I'm wrong in this, but wouldn't Netflix being throttled call for some kind of lawsuit? After all it is a network with original programming. Cable television doesn't buffer. Why should Netflix suffer? They are the same as the larger Cable networks, just delivered in a different way.

Same like pirating is stopped for music. By offering a service that is actually better than pirating. People are by default lazy and if they have a choice they will rather pay a bit than bother with pirating (this of course is not valid for people who can barely buy food as they have somewhat more important things to spend their money on and most likely have us to thank for that condition).

Actually, that is less about lazy and more about "Can be secure that the download does not have a virus in it that will mess up your machine!"

That is the main reason why I use Rhapsody Win 8 App for all or almost all my music listening today, I don't have to worry anymore about "Oh poop..... this thing had a virus in it and my anti-virus/anti-malware did not catch it!"

Ah yes. It is well known that viruses spread through video and sound files. While it technically might be possible I haven't heard about anything of the sort in the wild. Was a bug in gif or jpeg interpretation in windows a bunch of years ago that could result in buffer overflow but it was patched and is only case I've heard of.

Windows media files in particular have been known as a source of problems for years as they can contain URLs that by default will launch in internet explorer. There's also the avenue of rights management. The file can state it's rights managed by such and such URL on the internet causing Windows media player to retrieve the URL which has resulted in attacks. It's possible to put certain information in a video such that the decode explodes and crashes (Google's VP8 notably which they really ought to have sought community review before finalizing the spec as the problem was avoidable with the community's knowledge), potentially providing a way into a system. I haven't heard of any problems with Windows Media Player in years, but the attacks launched from video files are real. There have also been viruses that used an image file as the start of their attack.

I download random video and image files from the internet. I make it a point either to use Chrome to watch them, or scan them with AV first. I haven't had any problems. Actually when I think about it now, I've had a number of "corrupt" files that I just threw away. Mostly these were from Gnutella and iMesh in the days before Youtube existed. I didn't pay much attention to the files, they may have been attempted virus attacks.

I though Netflix paid for power, but I've done a little searching and the more I look the less likely it seems. If the costs of hosting the server are less than the cost of peering for the ISP without the ISP needing to spend capital to host the server then it would seem reasonable for the ISP to host the server, particularly as Netflix is 30% of peak US internet traffic and 20% overall. Here is an interesting breakdown of what Netflix's costs are and some ISP costs also.

Synergism to survive and retain value...Facing the same cost pressure, telecom operators and OTT content providers can partner to deliver quality services at lower bandwidth costs. The Open Connect model adopted between Netflix and operators is one such success......The USD7.99 monthly fee to each Netflix subscriber breaks down like this: Netflix pays USD3.00 for content rights, USD0.15 for CDN transmission, and USD2.26 for marketing and management. The monthly net profit of Netflix is USD2.58 per user. On the operator side, the ARPU is USD0.15 (from Netflix) plus USD29.99 (from broadband users). Netflix's services account for 30% of peak downstream traffic in North America, helping operators attract and retain valuable broadband users...http://www.huawei.com/en/solutions/insi ... v9-XvldWXo

How would it be if one day you log onto Netflix, and you get a popup that informs you that, 'Your ISP severely limits your quality level... Here's some other options in your area... Here's who to call, etc.'? Let's exhaust those options before we pay more government lawyers with money we don't have to do something that will likely fail in the courts anyway.

If you want a connection of 10mbps or more, most residential neighborhoods have one option and it is the cable provider. The core problem is that people can't vote with their wallets in this situation.

Streaming large files is a poor way of using network resources. Downloading via a peer to peer protocol for offline viewing is a much more clever and efficient way of using these resources. Unfortunately, the latter doesn't suit the powers that be.

If my understanding is correct, Spotify performs <music> streaming through P2P techniques.Should work for video streaming as well?

Streaming large files is a poor way of using network resources. Downloading via a peer to peer protocol for offline viewing is a much more clever and efficient way of using these resources. Unfortunately, the latter doesn't suit the powers that be.

If my understanding is correct, Spotify performs <music> streaming through P2P techniques.Should work for video streaming as well?

The petty games played with peering relationships are just ridiculous. And they get away with it because both sides point the finger at the other as the source of the problem, or blame the ISP for using that route.

If a VPN or DNS change 'fixes' the problem, the issue is entirely political in nature and could easily be corrected if the guilty parties were required to.

This would not be proof that Verizon or Comcast is throttling Netflix or any specific application.

I just prefer to go with the old saying... If it walks like a duck and it looks like a duck, then it's probably a duck.Plus, it wouldn't be bad for a change to switch the burden of proof onto the big telcos and make them show to the customers that they are not doing anything funky.

Otherwise, next thing you know, they may start also throttling all VPN connections as well.

This explains a lot and is quite different than the ISP blame game going on. I found it highly questionable that all ISPs were simultaneously in cahoots making Netflix performance suddenly go bad. I also find it highly questionable that only Netflix appears to be having issues with HD video quality.

The VPN test seems to show pretty conclusively that Netflix can deliver HD video if they want to to the same household. It is their decision of what interconnects to congest or when to balance to other non-congested paths.

All the Cogent and peering blaming is interesting given Netflix is the one that chooses which interconnect to use to reach ISPs and they can easily "on Monday I'll send on link 1 and on Tuesday I'll send on link 2, and then congestion will appear and subscribers will have a bad experience."

I think it is a safe bet that Netflix is the one running the "peering playbook" and all the reporters they are feeding the blame game should be questioning all those interviews.

I can't find the reference, but I remember an Ars article on this topic. It said that typically the amount of money involved in disputes over who pays for the data transfer (source side or demand side) is pretty small. That article seemed to suggest it was more a pissing match over power than over money.

If it can be repeatedly demonstrated that Netflix (or any other content provider, for that matter) is significantly faster over an encrypted VPN than otherwise, that's pretty solid evidence that your ISP is actively and selectively degrading service.

If it can be repeatedly demonstrated that Netflix (or any other content provider, for that matter) is significantly faster over an encrypted VPN than otherwise, that's pretty solid evidence that your ISP is actively and selectively degrading service.

That would be true with DPI technology and active traffic manipulation. They got caught with that years ago and stopped all of it. It is also easily detected now and Netflix would figure it out and would be happy to publish about it.

ISP throttling is not happening and the Netflix CEO even admitted to that.

It actually appears it is Netflix deciding the performance / ISP given the Netflix Client and CDN decides the server and path to deliver. If the interconnects are congested and still being used (vs balancing load), it is a Netflix choice. The VPN test proves this